Extend iris.common.resolve.Resolve to implicitly use target cube data

[bjlittle]

✨ Feature Request

Motivation

Extend iris.common.resolve.Resolve such that Resolve(src, tgt)() is possible instead of Resolve(src, tgt)(tgt.data).

It's a slightly easier pattern to tolerate, instead of forcing the user to explicitly pass in the data of the resultant resolved cube. So here the assumption is that the Resolve instance can use the target cube data (which may require to be broadcast automagically) if no data is provided for the resulting resolved cube.

This is in light of the deprecation of iris.util.as_compatible_shape, reference #3892.